1. Field of the Invention
The present invention relates to an air tap assembly, and more particularly to an air tap assembly for an automatically inflatable air cushion.
2. Description of the Related Art
A conventional air tap in accordance with the prior art shown in FIG. 7 comprises an air pipe 10, and a valve cap 20. The air pipe 10 has a first end formed with a toothed portion 16 inserted into the valve seat 30 of the air cushion 32 and a second end formed with a locking portion 12 formed with an annular groove 13 for receiving a washer 11. The air pipe 10 has an inner wall formed with an air conduit 101 communicating with the valve seat 30 of the air cushion 32 and an outer wall formed with an outer thread 14 and a plurality of snapping portions 15. The valve cap 20 is mounted on the air pipe 10 and has a top formed with an adjusting valve 21 mounted in the annular groove 13 of the air pipe 10 and rested on the washer 11. The adjusting valve 21 of the valve cap 20 has a distal end formed with a conical portion 23 inserted into the washer 11. The top of the valve cap 20 is formed with a plurality of air vents 22 each communicating with the air conduit 101 of the air pipe 10 when the adjusting valve 21 of the valve cap 20 is detached from the annular groove 13 of the air pipe 10. The valve cap 20 has an inner wall formed with an inner thread 24 screwed on the outer thread 14 of the air pipe 10. Thus, the valve cap 20 can be rotated relative to the air pipe 10, so that the adjusting valve 21 of the valve cap 20 is detached from the annular groove 13 of the air pipe 10, thereby connecting the air vents 22 of the valve cap 20 with the air conduit 101 of the air pipe 10, so as to inflate or deflate the air cushion 32.
However, the conical portion 23 of the adjusting valve 21 of the valve cap 20 is inserted into and detached from the washer 11 successively due to rotation of the valve cap 20, so that the washer 11 easily produces elastic fatigue, thereby decreasing the sealing effect. In addition, the washer 11 is easily displaced due to movement of the adjusting valve 21 of the valve cap 20, thereby decreasing the sealing effect. Further, the inner thread 24 of the valve cap 20 is successively rotated by the valve cap 20 to be screwed on and unscrewed from the outer thread 14 of the air pipe 10, thereby slowing the inflating process, and thereby easily wearing the inner thread 24 of the valve cap 20 and the outer thread 14 of the air pipe 10.